標題: Physicochemical and electrochemical properties of the (fluorosulfonyl) (trifluoromethylsulfonyl)amide ionic liquid for Na secondary batteries
作者: Yang, Huan
Luo, Xu-Feng
Matsumoto, Kazuhiko
Chang, Jeng-Kuei
Hagiwara, Rika
材料科學與工程學系
Department of Materials Science and Engineering
關鍵字: Na secondary batteries;Ionic liquids;(fluorosulfonyl)(trifluoromethylsulfonyl)amide;Hard carbon
公開日期: 15-九月-2020
摘要: In this study, thermal, physical, and electrochemical properties of the ionic liquid electrolyte system, Na[FTA]-[C(3)C(1)pyrr][FTA], (FTA(-) = (fluorosulfonyl) (trifluoromethylsulfonyl)amide and C(3)C(1)pyrr(+) = N-methyl-N-pro-pylpyrrolidinium) have been investigated for Na secondary batteries. The asymmetric FTA. structure provides a wide liquid-phase temperature range, especially at low x(Na[FTA]) (x(Na[FTA]) = molar fraction of Na[FTA]) and low temperature range. Glass transition at 170-209 K is the only observed thermal behavior in the x(Na [FTA]) of 0.0-0.4. Temperature dependence of viscosity and ionic conductivity obeys the Vogel-Tammann-Fulcher equation, and the correlation between molar conductivity and viscosity follows the fractional Walden rule. The anodic potential limits are above 5 V vs. Na+/Na at 298 and 363 K. The noticeable effects of x(Na [FTA]) are observed in the electrochemical performance of Na metal and hard carbon electrodes. In both cases, a moderate concentration, x(Na[FTA]) of 0.2-0.3, enables favorable charge-discharge behavior. At 363 K, the discharge capacities of the hard carbon electrode at x(Na[FTA]) of 0.3 are 260 and 236 mAh g(-1) at the current densities of 20 and 200 mA g(-1), respectively. The optimum cycling performance occurs at x(Na[FTA]) = 0.3, providing satisfactory capacity retention and high average Coulombic efficiency.
URI: http://dx.doi.org/10.1016/j.jpowsour.2020.228406
http://hdl.handle.net/11536/155000
ISSN: 0378-7753
DOI: 10.1016/j.jpowsour.2020.228406
期刊: JOURNAL OF POWER SOURCES
Volume: 470
起始頁: 0
結束頁: 0
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